Woodworking machine



March 16, 1943. M. M. TEAGUE WOODWORKING MACHINE Filed July 50, 1941 4Sheets-Sheet l MONROE P7. Enau:

3nnentor WM ram '(Ittornegs Marc-B16, 1943.

M.-M. TEAGUE WOODWORKING MACHINE Filed July 3'0; 1941 4 Sheets-Sheet 2attorney 5 March 16, 1943. M. M. TEAGUE 2,314,179,

WOODWORKING MACHINE Filed July so, 1941 4 Sheets-Sheet s Mommas PLTEnauaZhwentor m uum 4A6 attornegs March 16, 1943. .M TEAGUE 2,314,179

WOODWORKING MACHINE Filed July 30, 1941 4 Sheets-Sheet 4 p. 8o as ig gas l 86 I Jrwentor: Fig: 9 7 Memo: l lTsnsus mum" attorney s PatentedMar. 16, 1943 UNITED STATES PATENT OFFICE 2,314,179 WOODWORKING MACHINEMonroe M. Teague, Lenoir, N. C.

Application July 30, 1941, Serial No. 404,709

3 Claims.

This invention relates to wood working machines and more especially to amachine having novel provisions for cutting mortises in the edges ofboards. These mortises are adapted to receive tenons which are cut inanother board to thereby form a dovetailed connection.

It is an object ofthis invention to provide a mortise cutting machineequipped with means for automatically clamping and moving a workpieceinto engagement with'cutting elements to cause the mortises to be cut,and then to automatically retract the workpiece from the cuttingelements while unclamping the same.

It is another object of this invention to provide a mortise cuttingmachine having means for holding the workpiece for a predetermined timeinterval in its most advanced position relative to the cutting elementsto thereby insure that each mortise will be cut and reamed to the samesize and depth. This time interval is a rest period, during which thecutting elements are rotating in the deepest portions of the mortises.Where the workpiece is immediately retracted, after reaching its mostadvanced position, the depth of the mortises will vary according to thetype of material used. For example, where hard material is used, thecutters often flex or bend slightly as the workpiece is advanced. ,If ahard workpiece is suddenly reversed after being advanced, the mortisewill not be cut or reamed to the desired depth. On the other hand, if asoft material is used as a workpiece, this bending or flexing of thecutters will notoccur; consequently the mortises will be .cut thedesired depth. However, by providing a rest period, for the. workpiecewhen advanced to extreme cutting position, the cutters will have timetocut the mortises in the hard material to the same depth asin softmaterial.

It is another object of thisinvention to provide a machine of the classdescribed having an ad- ,iustment. forregulating the depth of mortisecut, an adjustable timing means for controlling the automatic, clampingand releasing mechanism, and also means for varying the amount ofpressure exerted by the clamp upon the workpiece when in advancedposition.

Some of. the o bjects of the invention having been stated, other objectswill appear as the description proceeds, when taken in connection withthe accompanying drawingsin which- Figure 1 is a plan view, with certainportions .thereof shown in section, illustrating a dovetailing machineembodying the present invention;

Figure 2 is an elevation looking at the right hand side of Figure 1;

Figure 3 is a vertical sectional View taken through the upper portion ofthe dovetailing machine along the line 3--3 in Figure 1;

Figure 4 is a front elevation with certain portions thereof in section,and taken along the line 4-4 in Figure 1;

Figure 5 is a rear elevation looking along the line 5-5 in Figure 1; V

Figure 6 is an isometric view showing a portion of a board in whichmortises have been cut with the present mechanism;

Figure 7 is a plan view looking from the near side of the board shown inFigure 6;

Figure 8 is an end view of the board shown in Figure 7;

Figure 9 is a timin diagram for various elements .constituting theinvention.

Carriage structure Referring more particularly to the drawings, thenumerals l0 denote suitable side frames which are held in spacedrelation to each other by any suitable means such as cross piece I Idisposed near the upper ends of the side frames. This cross piecesupports a suitable frame l2 and the upper portion of this framesupports suitable parallel spaced mortised guideways or pieces I4 which,in turn, accommodate suitable tenons 15 of a carriage bracket IS. Theupper surface of the carriage bracket I6 is inclined as at H. Thisinclined surface supports an L-shaped table member l8 which, in turn,supports a board or workpiece IQ for mortising operations. The tablemember [8 is adjustably held in position upon the surface I! by means ofsuitable adjustment screws 20, said screws being threadably secured inupstanding strap members 23, extending upwardly from the carriagebracket (6. By manipulating the screws 20 the L-shaped table member I8may be moved to the right or to the left upon inclined surface I! inFigure 3 to thereby vary the elevation of the upper horizontal surfaceupon which the workpiece I9 is adapted to rest. The parts I5, I6, I1,[8, 2B and 23 constitute a carriage which reciprocates back and forthbetween mortised guideways l4 during the operation of the machine.

Carriage reciprocating mechanism -30 are pivotally secured as at 31 tothe bracket I6, the other end of said links being pivotally secured tothe upper end of a lever 33. This lever 33 has its lower end fixedlysecured around a shaft 35, which in turn is mounted for oscillationbetween the side frames I9. Also fixedly secured upon the shaft 35 is asecond lever 31, and the free end of lever 31 has a roller 38 on itsfree end. The members 33, 35, and 31, constitute a bell crankarrangement for oscillating the carriage.

Roller 38 follows the periphery of a cam 40, and also passes throughgrooved or closed portion 59. 4|, which extends from a gear reductionhousing 42. Suitable reduction gears (not shown) are disposed withinthis housing, and these gears are driven by a conventional motor 43.

Carriage stroke adjustment The cam 49, shaft 4|, gear reduction housing42 and motor 43 are mounted upon a suitable bracket 44 which bracket issecured to the side of one of the side frames I (Figure 2) by anysuitable means such as stud bolts 45. These stud bolts 45 penetrateslots 46 in the bracket 44 and have the ends thereof threadably securedin the side frame Ill. The purpose of the vertically disposed slots 46is to permit vertical adjustment of the position of the bracket 44 andits associated load when it is desired to regulate the depth of mortisein workpiece I9. In order to provide for a minute vertical adjustment ofthe bracket 44, a vertically-disposed rod 48 is rotatably mounted in asmooth bore 49 in side frame I0. The lower end of rod 48 is threadablymounted in an outstanding leg 44a of the bracket 44 (see Figures 2 and4). When it is desired to vary the height of the bracket 44 and itsassociated mechanism and consequently to vary the carriage strokerotative to the cutting element, it is only necessaryto loosen the studbolts 45 and then turn the bolt 48 in the desired direction to cause thebracket to be raised or lowered. When the bracket has been properlypositioned, the stud bolts 45 are again tightened to hold the parts inadjusted position. In other words, the purpose of vertically adjustablebracket 44 along with the associated cam 40 is to vary the position ofthe extreme limits of the carriage stroke and therefore vary the depthof mortise out in the workpiece.

When the bracket 44 and cam 49 are moved upwardly from the positionshown in Figure 2, then the oscillation of the carriage to the rightwill be farther. On'the other hand if it is desired to reduce thedistance that the carriage moves to the right, it will be necessary tolower .the bracket 44 and the associated cam 49 from the position shown.

The cam- 40 has associated therewith a closed or grooved portion 50which is adapted to pass over the roller 38 during a partial revolution,that is while the carriage is moving from right to left in Figure 2. Thepurpose of this grooved runway 50 is to provide positive means forreturning the carriage from advanced position. In the present instancethe roller 38 is disposed on the uncovered periphery of the cam 49 andtherefore as the cam rotates in a clockwise direction from the positionshown, the carriage will move to the right in Figures 2; whereas whenthe groove 50 is passingover the roller, the carriage will move to theleft.

Cutting mechanism and driving means therefor The carriage moves back andforth between This cam is fixedly secured upon a shaft mortisedguideways I4, toward and away from suitable rotary cutters 55. The upperends of these rotary cutters are disposed slightly above the tophorizontal surface of table member I8 and have substantially the sameshape as an inverted frustro-conical member. As the carriage moves theworkpiece I 9 to the right in Figure 3 and into engagement with thesecutters 55, frustro-conical mortises or notches 56 are cut in the edgeof the workpiece. The depth of each frustro-conical notch from the edgeof the board is usually about the same as the diameter of the rotarycutter; however, it may be of any desired depth without departing fromthe spirit of the invention. The depth of this mortise from the face ofthe board, however, is usually somewhat less than the thickness of theworkpiece, that is if a blind mortise is being cut. Each of the cutters55 is fixedly secured upon the upper end of a vertically disposedrotatable shaft 51, said shaft being mounted in a suitable framework 58,which is secured between the side frames II). Byreferring to Figure 5,it will be seen that the intermediate portion of each shaft 51 has aspiraled gear 69 fixedly secured thereon. The gears 69 on the adjacentshaft 51 mesh with each other. In the present embodiment there are twosets of shafts 51 of five each, and upon each shaft a pinion 60 ismounted, the adjacent pinions in each set meshing with each other. Oneof the pinions 59 of each set is adapted to mesh with a driving gear 59on the upper end of a vertically disposed shaft BI (Figure 2). Shaft BIis rotatably mounted in bearings 62 and 63, and the lower end of theshaft 6| has fixedly secured thereon a beveled gear 64. This beveledgear meshes with a second beveled gear 65 on main drive shaft 66, saiddrive shaft having a suitable drive pulley 61 fixedly secured on the endthere- Upon the rotation of the pulley 61 from any suitable source ofpower, the cutters 55 are rotated, and therefore when the carriage andworkpiece I9 are advanced to the right in Figures 2 and 3. suitablefrustro-conical mortises or notches 56 will be cut in the edge of theworkpiece (see Figures 3, 6, '1, and 8). It is therefore seen that thecarriage and associated workpiece are positively and automaticallyadvanced into engagement with the cutters 55 and a so positively andautomatically withdrawn therefrom after the mortises have been cut.

Especial attention is called to the shape of the cam 40 (Figures 2 and9) It is here seen that as the cam 40 continues its clockwise rotationfrom the position shown in Figure 2, the roller 38 continues to rise tothereby rotate the shaft 35 to cause the workpiece I9 to be moved intoengagement with the cutters 55. After the cam 40 has rotatedsubstantially 45 degrees from the position shown, the carriage and theworkpiece I9 will have advanced to its farthest position relative to thecutters 55, after which the roller and carriage will remainsubstantially in the same position for another degrees of rotation ofthe cam because the radius of the cam remains the same (see Figure 9).When the roller 38 is disposed on this constant radius, the workpiece I9is held in engagement with the cutters 55 to permit the mortises to bethoroughly reamed. There is a very distinct advantage in providing thisdwell or rest period during which the cutters 55 are disposed in thedepth of the mortises 56. For example, where extremely hard material I9is used, there is a tendency for the cutters 55 to bend or flex when theworkpiece is moved into engagement therewith or the wood may becompressed in the cutting operation and then will spring back torestrict the cavity cut by-the cutters, and if the workpiece isimmediately withdrawn after reaching the extreme advanced position, thecutters will not completely ream the hole as deeply as it should be.However, by permitting the cutters to remain in the depth of themortises for an appreciable length of time, the mortises will be reamedcompletely to the same depth regardless of the hardness or resiliency ofthe workpiece.

Automatic workpiece clamping mechanism.

It is very essential that the workpiece be held in exactly the properposition during a mortising operation. To this end, a suitable brackethas been fixedly secured upon the upper portion of carriage bracket Itby any suitable means such as bolts 12. which accommodates a suitablehorizontally disposed clamping member 14, said member being disposed onthe lower ends of vertical slidably mounted shafts 15. The upper ends ofthe shafts I5 have rotatably mounted therein, suitable pivot projectionsHi which are eccentrically mounted in each end of a transverse shaft Tl.Shaft 11 is mounted in alined stationary oval-shaped slots 18 in theupper ends of eye bolts 19. Figures 2 and 3 clearly show the position ofeccentric pivot projections 16 relative to shaft l1 and slot 18. Sincethe slots 18 in the members 19 are held in stationary position, it isevident that as the shaft 1! rotates about pivots 16 the rods l5 andclamping members 14 will be raised or lowered, depending upon thedirection of rotation of the shaft.

The intermediate portion of the shaft 11 has a lever 80 extendingupwardly therefrom and fixedly mounted thereon. This lever has pivotallysecured thereto as at 8 l a horizontally disposed rod 82, which rod hasthe intermediate portion thereof slidably mounted in a smooth bore 83 ina block 84. Block 84 is fixedly mounted between suitable pivot screws 85in the vertical legs of angle brackets 86, said brackets 85, in turn,being supported by an angle frame 81 extending upwardly from side framesHi. Threadably mounted around the rod 82 adjacent the lever 80 aresuitable nuts 39, which confine one end of a suitable compression spring90 around the rod and at the same time hold the other end of compressionspring against the block 84.

As the cam rotates in a clockwise direction in Figure 2, toautomatically advance the carriage mechanism and workpiece l9 toward thecutters 55, the spring 90 will automatically be compressed to yieldinglyrotate the lever 80 and shaft Ti in a counter-clockwise manner (Figures2 and 3), to lower the clamping member 14 upon the workpiece 19.

In the operation of the present apparatus the workpiece is firstpositioned on top of table member I 8. As the table member l8 and theworkpiece advance toward the cutters the clamping mechanism will beautomatically lowered into yielding engagement with the workpiece, tohold the same in clamped position upon the table it while the mortises56 are being out (see Figure 9) The purpose of providing the sliding fitbetween the block 84 and rod 82 is to permit spring 99. to be compressedas the clamp plate i4 is being lowered. In other words, where there is aslight variation in the thickness of the workpiece 19, the clamp M willbe automatically moved into clamping engagement therewith. Any farthermovement of the carriage toward the cutters will The bracket has ahollow portion 13 not affect the clamping means material-1y but willonly serve to compress the spring 90.

Where it is desired to vary the amount of initial pressure exerted bythe clamping member M upon the workpiece, it is only necessary tomanipulate the nut $9 on the rod 82 to vary the pressure on spring 93. Afurther adjustment can be made by loosening suitable set screws 19a sothat the elevation of eye bolts 19 can be changed.

It will be noted that the cutters 55 are disposed substantially in astraight line (Figure 1). When cutting, a plurality of alined mortisesin the edge of the workpiece, it is important that the mor-tised edge beheld in parallel relation to the line of cutters so that each mortisewill be cut exactly the same depth from the edge. In order to performthis function properly it is necessary to have a suitable stop platesuch as 199'. The ends of this plate are slidably mounted aroundshouldered bolts llll disposed at each end of the bracket'lil. The loweredge of this plate extends downwardly, slightly'below the top edge ofthe workpiece it (Figure 3), but terminates slightly above the top ofthe cutters 55, so that the plate may move with the carriage over thecutter members without contacting the same. The plate N10 is held inengagement with the right-hand face of bracket 10 (Figures 2 and 3), bymeans of a suitable eccentrically mounted roller I04, said roller beingpivoted as at I05 in the enlarged head portions of bolts NH. The rollerI04 is turned by means of a suitable lever I06 when it is desired toclamp or release the plate I00.

It is therefore seen that I have provided a simple apparatus which iscapable of simultaneously cutting a plurality of mortises of uniformdepth in the edge of a workpiece. This apparatus is simple inconstruction, easy to manufacture, and automatically operated, thuseliminating many hand operations which have heretofore been necessary incutting mortises.

In the drawings and specification, there has been set forth a preferredembodiment of the invention, and although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being set forth inthe claims.

I claim:

1. A machine clamp including a framework, a table for supporting aworkpiece, means slidably mounting the table in the framework, saidtable being movable towards and away from an operative position, andmeans for automatically clamping the workpiece on the table as it movestowards the operative position and for releasing it as the table movesaway from the operative position, the clamping means including avertically movable clamping member slidably mounted with respect to thetable, an eccentric member pivoted with respect to the table and havingconnection with the vertically slidable member for operating the same, alever on said eccentric member, a link carried by said lever and beingslidably mounted in a portion of the framework, a spring on said linkfor normally holding the vertically movable clamping member in raisedposition and serving to retard bodily movement of said lever as saidtable is moved to operative position to oscillate said eccentric and tothereby lower and resiliently press the verticall movable clampingmember into engagement with the workpiece as the table is so movedforwardly.

2. A machine clamp comprising a framework,

a table for supporting the workpiece, means slidably mounting said tablein the framework for movement towards and away from an operativeposition, a superstructure on the table, clamping means for theworkpiece mounted in the superstructure and including a verticallyslidable member for engaging the workpiece, an oscillatory eccentricmember in the superstructure for operating the vertically slidablemember, a lever on the eccentric member, a link pivotally connected atone end to the lever, a support rising from the framework, means on thesupport for slidably supporting the link, a compression spring disposedon the link for retarding movement of one end of said lever as the tablemoves to the operative position to effect oscillation of said lever tomove the vertically slidable member downwardly as the table is ad vancedtowards the operative position to press the workpiece against the tablebefore the workpiece is presented at the operative position of saidtable.

3. A clamp including a framework, a table, means mounting said table formovement from an operative position to an inoperative position, means onthe table for clamping a workpiece while it is moved to its operativeposition, said means comprising a bracket disposed above the table, avertically movable clamping member slidably mounted on the bracket, aneccentric member pivoted on the bracket and having connection With thevertically slidable member for operating the same, a lever on saideccentric member, a link carried by said lever and being slidablymounted in a portion of said framework, a spring on said link fornormally holding the vertically movable member in raised position andserving to retard bodily movement of said lever as said table is movedto operative position to oscillate said eccentric and thereby to lowerand resiliently press the vertically movable clamping member intoengagement with the workpiece as the table is so moved.

MONROE M. TEAGUE.

